1. Field of the Invention
The present invention relates to a pattern image comparison technology and, more specifically, to a technology of comparing a pattern image of design data and a pattern image of a reticle mask or semiconductor device.
2. Description of the Related Art
In fabrication of a reticle mask in recent years, the quality of the reticle mask depends on whether a pattern transferred onto a substrate such as a semiconductor wafer or the like can accurately reproduce a design pattern by performing an OPC processing (Optical Proximity Correction method).
However, an auxiliary pattern or the like for use in the OPC processing and the like may be formed into a different pattern due to a change not only in dimension but also in form or area. To assure the transferred pattern, what is required hereafter is assurance by form, area, or the like using a two-dimensional pattern. Further, the pattern form needs to be managed through use of a numeric value (defining as no problem to values less than a certain value) for assurance of the pattern form. Conventionally, there has been no definition of converting the pattern form into a numeric value, causing great difficulty in setting of a tolerance.